Hypertension and hypercholesterolemia are important modifiable risk factors for cardiovascular disease (CVD). We examined the prevalence, treatment, and control of combined hypertension and hypercholesterolemia in United States adults aged>or=20 years (n=2,864, projected to 118 million, 52% women) from the National Health and Nutrition Examination Survey 2001 to 2002 by gender, age group, ethnicity, and co-morbidities (metabolic syndrome, diabetes mellitus [DM], and preexisting CVD). Hypertension was defined as blood pressure of >or=140/90 mm Hg (>or=130/80 mm Hg if DM was present) or on treatment. Hypercholesterolemia was defined as a low-density lipoprotein cholesterol level of >or=130 mg/dl (>or=100 mg/dl if DM or CVD was present) or on treatment. The overall prevalence of hypertension, hypercholesterolemia, and hypertension and hypercholesterolemia combined was 30%, 47%, and 18%, respectively. The incidence of the 2 combined was 20% in women versus 16% in men (p<0.05), ranging from 1.9% in those aged 20 to 29 years to 56% in those aged>or=80 years (p<0.001). Combined hypertension and hypercholesterolemia was least prevalent in Hispanics (9.8% compared with 19% in whites and 22% in African-Americans, p<0.01) and highest in those with CVD plus DM or metabolic syndrome (69%), CVD only (44%), DM only (41%), and metabolic syndrome only (37%). Of those with combined hypertension and hypercholesterolemia, 29% were being treated (8.3% in those aged 20 to 29 years to 38% in those aged 70 to 79 years, p<0.01). Treatment was least prevalent in Hispanics (12% vs 24% in African-Americans and 30.4% in whites, p<0.01). Overall control of hypertension and hypercholesterolemia was only 9% and was low in all disease groups (5.5% to 16%). In conclusion, treatment and control of combined hypertension and hypercholesterolemia are suboptimal. Increased efforts to improve treatment of these conditions are needed.